TI-BASIC:Arctan
Command Summary
Returns the inverse tangent (also called arctangent)
Command Syntax
tanֿ¹(number)
Menu Location
Press:
- [2nd]
- [tanֿ¹]
TI-83/84/+/SE
1 byte
tanֿ¹( returns the arctangent of its argument. It is the inverse of Tan(, which means that tanֿ¹(n) produces an angle θ such that tan(θ)=n.
Like tan(, the result of tanֿ¹( depends on whether the calculator is in Radian or Degree mode. However, unlike tangent, the result is in degrees or radians, not the argument. A full rotation around a circle is 2π radians, which is equal to 360°. The conversion of θ=tanֿ¹(n) from radians to degrees is θ*180/π and from degrees to radians is θ*π/180. The tanֿ¹( command also works on a list.
tanֿ¹( will always return a value between -π/2 and π/2 (or -90° and 90°).
In radians:
:tanֿ¹(1) .7853981634
In degrees:
:tanֿ¹(1) 45
Optimization
Expressions of the form tanֿ¹(y/x) are usually better recast as R►Pθ(x,y); the latter will not fail even if x should happen to be equal to zero.
Error Conditions
- ERR:DATA TYPE is thrown if you input a complex value or a matrix.